SRS Antenna Port Switching for Accurate NR Timing Measurement

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Solution Overview

Problem

Antenna port switching during SRS transmissions in NR wireless communication systems can lead to transmit time misalignment errors (TAE), resulting in significant positioning errors due to inconsistent timing measurements.

Innovation Solution

Adaptive timing measurement procedures are implemented by the UE or network nodes to mitigate the effects of antenna port switching, including limiting the number of switching actions, compensating for timing errors, or adjusting measurement periods to ensure accurate timing measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If antenna port switching is performed during SRS transmissions, then transmit diversity and signal reliability are improved, but transmit time misalignment errors occur resulting in positioning inaccuracies

Engineering Contradiction:
Improvesignal reliabilityVSAvoidtiming measurement accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The network configures the UE with a timing alignment offset value before antenna port switching occurs. This preliminary configuration enables the UE to pre-calculate and apply timing adjustments, ensuring that timing measurements remain accurate even when antenna ports are switched during SRS transmissions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The network receives timing measurement results from the UE and uses this feedback to adjust and update timing alignment offset values. This closed-loop feedback mechanism allows the system to continuously optimize timing alignment, compensating for any drift or misalignment that occurs during antenna port switching operations.

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If the number of antenna port switching actions is increased, then measurement coverage and adaptability are improved, but timing misalignment errors increase

Engineering Contradiction:
Improvemeasurement adaptabilityVSAvoidtiming measurement accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system dynamically adjusts the timing alignment offset parameter based on the number of antenna port switching actions performed. When multiple switching actions are detected, the offset value is modified to compensate for cumulative timing drift, allowing the system to maintain measurement precision even with increased adaptability.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If timing measurement procedures are made more adaptive to handle antenna switching, then positioning accuracy is improved, but system complexity increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidmeasurement procedure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The UE autonomously determines whether antenna port switching has occurred during SRS transmissions and automatically applies the appropriate timing alignment offset without requiring complex network coordination. This self-service approach enables adaptive timing compensation while keeping the system relatively simple.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The network provides timing alignment offset configurations in advance through RRC signaling, allowing the UE to have the necessary correction parameters ready before measurements begin. This preliminary provision of parameters simplifies the measurement procedure by eliminating the need for complex real-time calculations and negotiations.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4278471B1Timing measurement procedure under SRS antenna port switching
Publication Date: 2026.03.04 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP4278471B1 patent drawingFigure 1~2
  • EP4278471B1 patent drawingFigure 3~4
  • EP4278471B1 patent drawingFigure 5~6

AI summary

A method of operating a wireless device that is configured to perform a timing measurement procedure that involves transmission of a reference signal during a timing measurement period is disclosed. The method includes determining that the wireless device is configured for antenna port switching of an antenna port configuration for transmitting the reference signal during the timing measurement period, and in response to determining that the wireless device is configured for antenna port switching of the antenna port configuration for transmitting the reference signal during the timing measurement period, adapting at least one of the timing measurement procedure during the timing measurement period and a configuration for antenna port switching of the antenna port configuration for transmitting the reference signal during the timing measurement period.